A singular matrix is a square matrix which is not invertible. Alternatively, a matrix is singular if and only if it has a determinant of 0. When an matrix is taken to represent a linear transformation in n-dimensional Euclidean space, it is singular if and only if it maps any n-dimensional hypervolume to a n-dimensional hypervolume of zero volume.
- Weisstein, Eric W. "Singular Matrix". mathworld.wolfram.com. Retrieved 2019-11-03.